From: Zhizhou Zhang Date: Tue, 12 Jun 2018 09:07:37 +0000 (+0800) Subject: arm64: make secondary_start_kernel() notrace X-Git-Tag: v5.15~8556^2~2 X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=b154886f7892499d0d3054026e19dfb9a731df61;p=platform%2Fkernel%2Flinux-starfive.git arm64: make secondary_start_kernel() notrace We can't call function trace hook before setup percpu offset. When entering secondary_start_kernel(), percpu offset has not been initialized. So this lead hotplug malfunction. Here is the flow to reproduce this bug: echo 0 > /sys/devices/system/cpu/cpu1/online echo function > /sys/kernel/debug/tracing/current_tracer echo 1 > /sys/kernel/debug/tracing/tracing_on echo 1 > /sys/devices/system/cpu/cpu1/online Acked-by: Mark Rutland Tested-by: Suzuki K Poulose Signed-off-by: Zhizhou Zhang Signed-off-by: Catalin Marinas --- diff --git a/arch/arm64/kernel/smp.c b/arch/arm64/kernel/smp.c index f3e2e3ae..2faa986 100644 --- a/arch/arm64/kernel/smp.c +++ b/arch/arm64/kernel/smp.c @@ -179,7 +179,7 @@ int __cpu_up(unsigned int cpu, struct task_struct *idle) * This is the secondary CPU boot entry. We're using this CPUs * idle thread stack, but a set of temporary page tables. */ -asmlinkage void secondary_start_kernel(void) +asmlinkage notrace void secondary_start_kernel(void) { u64 mpidr = read_cpuid_mpidr() & MPIDR_HWID_BITMASK; struct mm_struct *mm = &init_mm;